# a binary search tree of values like Java's TreeSet<E>

class Tree
  def initialize
    @overall_root = nil
  end

  def insert(v)
    @overall_root = insert_helper(v, @overall_root)
  end

  def print
    print_helper(@overall_root)
  end

  private

  class Node
    def initialize(data = nil, left = nil, right = nil)
      @data = data
      @left = left
      @right = right
    end

    attr_reader :data, :left, :right
    attr_writer :data, :left, :right
  end

  def insert_helper(v, root)
    if root == nil
      root = Node.new(v)
    elsif v < root.data
      root.left = insert_helper(v, root.left)
    else
      root.right = insert_helper(v, root.right)
    end
    return root
  end

  def print_helper(root)
    if root
      print_helper(root.left)
      puts root.data
      print_helper(root.right)
    end
  end
end